Porsche Enthusiasts Club Forum

Almost certainly the viscosity and almost certainly the thinner oil was being pulled down the valve guides.

Whats considered acceptable oil pressure, hot at idle on an early 944 lux?

My "new" car seems to hover just over 2 bar on 10-40 semi which i thought a little on the low side.

Having blown one engine up, i don't want to make it two for the sake of thicker oil!

I would certainly expect 2bar or above on any 944 engine when hot and at idle.

Ideally 2.5 or above, but would not be concerned anywhere above 2

Aircooled 911 engines are often less than 1 bar at hot idle, and my dads old rolls royce peaks at 2.2 bar oil pressure and goes down to about 1 bar or less at idle.

Yes Jon, pretty sure it was the viscosity although I have always ran it with thinner and had no problems previously, maybe now is the time to use the thicker stuff, oil pressure is and always has been good (in my opinion) at 2.5 tick over when hot and 4.5/5 over 1500rpm, it just seems to bounce around less with the 10w40. I will keep an eeye on oil usage as it was high with the 5w40 and as you say I do suspect valve guide seals which when I can find someone to line bore the cam journals I will have replaced.

Thanks Jon, it is just over 2 bar - only just! I suppose the thing to do is to see if it uses any and maybe try a grade thicker at the next change?

Either way thanks for confirming i dont need to lose sleep yet i'll keep an eye on it.

May even be the seals on the oil pressure relief valve, or perhaps the valve itself which is bleeding off a little pressure.

Old thread I know, but as far as ZDDP in oil goes it seems that Comma eurolite 10w/40 semi is the most suitable for our cars. They are the only company that actually list the blend on the website !

0.18% zddp (1800 ppm)

That is good levels, cheap price too. I just ordered Miller's Trident 5w40 fully synthetic. I contacted Miller's technical team and they got back to me within the hour advising that it has over 1300ppm ZDDP. Pretty cheap too at just over £20 for 5 liters.

Good levels, but unsure about fully synthetic oil and a 5w as it may use a lot more oil than the 10w.

The Boxsters next oil change will be with Comma Race oil which is a 5W/50 & a sensible price from Car Parts Genie. 1100ppm of ZDDP & SL rated.

Does anyone suffer excessive oil usage using a 5w in a n/a 944 ?

The 5 being the cold viscosity may make the engine more prone to oil leaks when standing or warming up, possibly with oil consumption when warming up, but when up to temperature should be absolutely fine as the hot viscosity will be the same as a 15w50 or 20w50.

An interesting article I wrote a while ago for the website, but never got around to proof reading and following up on is here at this link

http://www.jmgporsche.co.uk/index.php/menu-articles/articles-maintenance/item/222-article-understandingoilspecspartone

Sticking with the 10w/40 semi Comma eurolite.
One day I may sway to a 10w/50 as it's a slightly ticky engine but don't want to create more resistance in the engine.

My next engine oil change is probably going to be with this stuff:
http://www.eurocarparts.com/ecp/p/car-a ... &0&cc5_253
That's Valvoline VR1 10w60 @ £59.94 per 5 litres

Apparently it has a good amount of ZDDP (0.13% / 1300ppm)
http://www.valvoline.com/faqs/motor-oil/racing-oil/

Would anyone care to comment?

It's a standard 220bhp 944 turbo with 130k miles on the clock.

Wants a high gold or cocaine content for that money :O